What about "phone" (short for telephone) or "auto" (short for automobile) or "flu" (short for influenza) - do you consider these abbreviations instead of words? English is an evolving language with new words added regularly. Often, yesterday's abbreviation becomes today's word. All word games need some sort of definitive reference for what is considered a valid word - seems like the Dordle folks are using Wiktionary as their source. If it's in Wiktionary, then it's a valid word.
The game tells you if the letter combo is considered valid - I've learned a couple new words that way :)